Image correction using one-dimensional correction factors

Abstract

This disclosure provides systems, methods, and devices for image signal processing that support image correction, including lens shading correction (LSC). In a first aspect, a method of image processing includes receiving first image data comprising a first image frame from a camera module; receiving one-dimensional lens shading correction (LSC) factors; and determining an output image frame based on the first image frame by: interpolating a plurality of correction values corresponding to two-dimensional locations of the first image frame by interpolating the one-dimensional lens shading correction (LSC) factors; and applying the plurality of correction values to corresponding locations of the first image frame, wherein applying the plurality of correction values corrects a lens shading effect of the camera module. Other aspects and features are also claimed and described.

What is claimed is: 
     
         1 . A method, comprising:
 receiving first image data comprising a first image frame;   receiving one-dimensional correction factors; and   determining an output image frame based on the first image frame by:
 determining a plurality of gain values corresponding to two-dimensional locations of the first image frame based on the one-dimensional correction factors; and 
 applying the plurality of gain values to corresponding locations of the first image frame to determine the output image frame. 
   
     
     
         2 . The method of  claim 1 , wherein receiving the one-dimensional correction factors comprises receiving one-dimensional lens shading correction (LSC) factors, and wherein applying the plurality of gain values corrects a lens shading effect of a camera module that captured the first image data. 
     
     
         3 . The method of  claim 2 , wherein the step of determining the plurality of gain values comprises interpolating gain values for pixels of the output image frame based on the one-dimensional correction factors. 
     
     
         4 . The method of  claim 2 , wherein receiving the one-dimensional lens shading correction (LSC) factors comprises:
 receiving a first plurality of one-dimensional lens shading correction (LSC) factors corresponding to a first line through the first image frame; and   receiving a second plurality of one-dimensional lens shading correction (LSC) factors corresponding to a second line through the first image frame.   
     
     
         5 . The method of  claim 4 , wherein determining the plurality of gain values comprises, for at least one pixel:
 determining a first distance from the at least one pixel to the first line;   determining a second distance from the at least one pixel to the second line; and   determining a gain value for the at least one pixel from the first distance, the second distance, the first plurality of one-dimensional LSC factors, and the second plurality of one-dimensional LSC factors.   
     
     
         6 . The method of  claim 4 , wherein the first line comprises a plurality of knee points. 
     
     
         7 . The method of  claim 4 , wherein the first line comprises a first diagonal through a center of the first image frame and the second line comprises a second diagonal through the center of the first image frame. 
     
     
         8 . The method of  claim 4 , wherein the first line comprises a curve and the first plurality of one-dimensional lens shading correction (LSC) factors comprises coefficients defining the curve. 
     
     
         9 . The method of  claim 1 , further comprising:
 determining the first image frame is recorded by a first camera module; and   requesting a first set of one-dimensional correction factors corresponding to the first camera module,   wherein receiving the one-dimensional correction factors comprises receiving the first set of one-dimensional correction factors corresponding to the first camera module.   
     
     
         10 . The method of  claim 1 , wherein receiving the one-dimensional correction factors comprises receiving a one-dimensional color correction factors for each of red, blue, and green channels, and wherein applying the plurality of gain values corrects a color aberration of a camera module that captured the first image data. 
     
     
         11 . An apparatus, comprising:
 a memory storing processor-readable code; and   at least one processor coupled to the memory, the at least one processor configured to execute the processor-readable code to cause the at least one processor to perform operations including:
 receiving first image data comprising a first image frame; 
 receiving one-dimensional correction factors; and 
 determining an output image frame based on the first image frame by:
 determining a plurality of gain values corresponding to two-dimensional locations of the first image frame based on the one-dimensional correction factors; and 
 applying the plurality of gain values to corresponding locations of the first image frame to determine the output image frame. 
 
   
     
     
         12 . The apparatus of  claim 11 , wherein receiving the one-dimensional correction factors comprises receiving one-dimensional lens shading correction (LSC) factors, and wherein applying the plurality of gain values corrects a lens shading effect of a camera module that captured the first image data. 
     
     
         13 . The apparatus of  claim 12 , wherein the step of determining the plurality of gain values comprises interpolating gain values for pixels of the output image frame based on the one-dimensional correction factors. 
     
     
         14 . The apparatus of  claim 12 , wherein receiving the one-dimensional lens shading correction (LSC) factors comprises receiving:
 a first plurality of one-dimensional lens shading correction (LSC) factors corresponding to a first line through the first image frame; and   a second plurality of one-dimensional lens shading correction (LSC) factors corresponding to a second line through the first image frame.   
     
     
         15 . The apparatus of  claim 14 , wherein determining the plurality of gain values comprises, for at least one pixel:
 determining a first distance from the at least one pixel to the first line;   determining a second distance from the at least one pixel to the second line; and   determining a gain value for the at least one pixel from the first distance, the second distance, the first plurality of one-dimensional LSC factors, and the second plurality of one-dimensional LSC factors.   
     
     
         16 . The apparatus of  claim 14 , wherein the first line comprises a plurality of knee points. 
     
     
         17 . The apparatus of  claim 14 , wherein the first line comprises a first diagonal through a center of the first image frame and the second line comprises a second diagonal through the center of the first image frame. 
     
     
         18 . The apparatus of  claim 14 , wherein the first line comprises a curve and the first plurality of one-dimensional lens shading correction (LSC) factors comprises coefficients defining the curve. 
     
     
         19 . The apparatus of  claim 11 , wherein the at least one processor is further configured to perform operations including:
 determining the first image frame is recorded by a first camera module; and   requesting a first set of one-dimensional correction factors corresponding to the first camera module,   wherein receiving the one-dimensional correction factors comprises receiving the first set of one-dimensional correction factors corresponding to the first camera module.   
     
     
         20 . The apparatus of  claim 11 , wherein receiving the one-dimensional correction factors comprises receiving a one-dimensional color correction factors for each of red, blue, and green channels, and wherein applying the plurality of gain values corrects a color aberration of a camera module that captured the first image data. 
     
     
         21 . A non-transitory computer-readable medium storing instructions that, when executed by a processor, cause the processor to perform operations comprising:
 receiving first image data comprising a first image frame;   receiving one-dimensional correction factors; and   determining an output image frame based on the first image frame by:
 determining a plurality of gain values corresponding to two-dimensional locations of the first image frame based on the one-dimensional correction factors; and 
 applying the plurality of gain values to corresponding locations of the first image frame to determine the output image frame. 
   
     
     
         22 . The computer-readable medium of  claim 21 , wherein receiving the one-dimensional correction factors comprises receiving one-dimensional lens shading correction (LSC) factors, and wherein applying the plurality of gain values corrects a lens shading effect of a camera module that captured the first image data. 
     
     
         23 . The computer-readable medium of  claim 22 , wherein the step of determining the plurality of gain values comprises interpolating gain values for pixels of the output image frame based on the one-dimensional correction factors. 
     
     
         24 . The computer-readable medium of  claim 22 , wherein receiving the one-dimensional lens shading correction (LSC) factors comprises receiving:
 a first plurality of one-dimensional lens shading correction (LSC) factors corresponding to a first line through the first image frame; and   a second plurality of one-dimensional lens shading correction (LSC) factors corresponding to a second line through the first image frame.   
     
     
         25 . The computer-readable medium of  claim 24 , wherein determining the plurality of gain values comprises, for at least one pixel:
 determining a first distance from the at least one pixel to the first line;   determining a second distance from the at least one pixel to the second line; and   determining a gain value for the at least one pixel from the first distance, the second distance, the first plurality of one-dimensional LSC factors, and the second plurality of one-dimensional LSC factors.   
     
     
         26 . An image capture device, comprising:
 an image sensor;   a memory storing processor-readable code; and   at least one processor coupled to the memory and to the image sensor, the at least one processor configured to execute the processor-readable code to cause the at least one processor to perform operations including:
 receiving first image data comprising a first image frame; 
 receiving one-dimensional correction factors; and 
 determining an output image frame based on the first image frame by:
 determining a plurality of gain values corresponding to two-dimensional locations of the first image frame based on the one-dimensional correction factors; and 
 applying the plurality of gain values to corresponding locations of the first image frame to determine the output image frame. 
 
   
     
     
         27 . The image capture device of  claim 26 , wherein receiving the one-dimensional correction factors comprises receiving one-dimensional lens shading correction (LSC) factors, and wherein applying the plurality of gain values corrects a lens shading effect of a camera module that captured the first image data. 
     
     
         28 . The image capture device of  claim 27 , wherein the step of determining the plurality of gain values comprises interpolating gain values for pixels of the output image frame based on the one-dimensional correction factors. 
     
     
         29 . The image capture device of  claim 27 , wherein receiving the one-dimensional lens shading correction (LSC) factors comprises receiving:
 a first plurality of one-dimensional lens shading correction (LSC) factors corresponding to a first line through the first image frame; and   a second plurality of one-dimensional lens shading correction (LSC) factors corresponding to a second line through the first image frame.   
     
     
         30 . The image capture device of  claim 29 , wherein determining the plurality of gain values comprises, for at least one pixel:
 determining a first distance from the at least one pixel to the first line;   determining a second distance from the at least one pixel to the second line; and   determining a gain value for the at least one pixel from the first distance, the second distance, the first plurality of one-dimensional LSC factors, and the second plurality of one-dimensional LSC factors.